Nitrogen Fertilizer Management to Mitigate N 2 O Emissions in Alberta

Transcription

1 Nitrogen Fertilizer Management to Mitigate N 2 O Emissions in Alberta Len Kryzanowski, P.Ag Section Lead, Land Use Section Alberta Agriculture and Rural Development

2 Acknowledgements R. McKenzie, J. O Donovan, A. Akbar, E. Smith, R. Dunn, T. Goddard Field and Lab Technical Support C. Sprout, A.B. Middleton, B. Henriquez, P. Pfiffer, D. Thiessen, C. Hietamaa, S. Jess, D. Werk, L. Powers, G. Lohstraeter L. Michelsen, P. Reid, J. Zuidof, G. Semech Funding Alberta Crop Industry Development Fund (ACIDF)

3 The Nitrogen Cycle Atmospheric Fixation Crop Harvest Atmospheric Nitrogen Industrial Fixation (Commercial Fertilizers) Volatilization NH 3 Animal Manures and Biosolids Biological Fixation By Legume Plants Organic and Microbial Nitrogen Plant Residues Ammonium NH 4 + Plant Uptake Nitrate NO 3 - N 2, N 2 O Denitrification Runoff and Erosion Component Input Loss Leaching Adapted from IPNI

4 Nitrogen Losses N-Cycle is open ended with many pathways for inputs and losses; control is difficult Large amounts of surplus reactive N (NH 3, NH 4+, NO x, HNO 3, NO 3, N 2 O and organic N forms) Volatilization, leaching, runoff, denitification Source: Manitoba Agriculture, Food and Rural Initiatives

5 N 2 O Concerns A significant greenhouse gas GWP times greater than CO 2 Ozone depleting agent Indicator of inefficiencies in N recovery from soil and fertilizer. Limiting N 2 O emissions from farming operations can be beneficial from both an environmental as well as an agronomic standpoint. IPCC established values to calculate direct N 2 O emissions from fertilizer N use in various parts of the world %. 5

6 Synchronizing Available N and Crop Uptake Low N recoveries by crops, i.e., low NUEs, Quick nutrient release characteristics of common fertilizers Nonresponsive to changes in soil water and temperature (factors regulating plant growth) Not coinciding with crop growth peak demands The gradual release of ammonium from controlled release N fertilizers provides a slow stream of nitrogen for plant uptake, and minimize N losses. 6

7 Metric Tonnes N 600,000 Nitrogen Fertilizer Use Fertilizer Nitrogen Sales for Alberta , , , , , Year

8 Management Options to Improve Nitrogen Use Efficiency Crop selection Legumes vs non-legumes Crop breeding Improve NUE Fertilizer management Implement N BMPs, 4R Nutrient Stewardship - Timing, placement, rates and sources Use enhanced efficiency fertilizers (EEF) with improved characteristics: Single application for the entire growing season High percentage uptake into the target crop Minimum detrimental effects on environment 8

9 Environmentally Smart Nitrogen (ESN) ESN is a polymer-coated urea (PCU) fertilizer Moisture and Temperature Controlled Adapted from "Olson-Rutz et al., Enhanced Efficiency Fertilizers (EB0188), Montana State Univ. Extension Schematic adapted from Agrium U.S., Inc. (Photos courtesy of Agrium U.S., Inc. All rights reserved.)

10 ESN Fertilizer Technology Development Project Collaborative 4 5 year study : AARD ESD (Land Use) RAID (Food & Bio-Industrial Crops) AAFC Lacombe, Beaverlodge Agrium ACIDF

11 Project Objectives Evaluate agronomic performance of urea, ESN and blend, for crop growth, yield and quality, based on 4R nutrient management system Right Right Rate, Right Time, Right Place Identify appropriate use of ESN, urea or blend (spring versus fall application, soil moisture conditions, agro-climatic regions and crop). Identify agronomic rate limits of ESN, urea and blend application to reduce seedling damage. Determine economic optimum rates, placement and timing of ESN, urea and blend application. Evaluate N fertilizer management to mitigate N 2 O emissions Update provincial N fertilizer management recommendations and the AFFIRM software.

12 Agronomic Research Design Study crop productivity, crop quality, maximum safe fertilizer rates, and N use efficiency: Compare effectiveness of N fertilizer sources - urea, ESN and blend (25% urea-75% ESN). Compare N fertilizer application time/placement - Fall Banded (FB), Spring Banded (SB), Spring Seed-Placed (SP) of urea and ESN - Spring Seed-Placed (SP) blend Crop response to increasing N fertilizer application rates (0, 30, 60, 90, 120 kg/ha). 3 Crops (HRS Wheat, 2R Barley and RR Canola)

13 Agronomic Research Locations 9 sites across Alberta 8 dryland & 1 irrigated Range of agro-ecological regions with various soil types and climatic regimes Continuously cropped or stubble fields Research Sites

14 N 2 O Research Locations Determine N 2 O emissions reduction from timing, rates and nitrogen fertilizer products (urea and ESN). 3 sites for N 2 O monitoring - 2 dryland & 1 irrigated - Dark Gray Luvisol - Black Chernozem - Dark Brown Chernozem Research Sites

15 N 2 O Research Design Evaluate N fertilizer management options to mitigate N 2 O emissions: Compare effectiveness of N fertilizer sources - urea, ESN. Compare N fertilizer application time - Fall Banded (FB), Spring Banded (SB), Compare N fertilizer application rates - 0, 60, 120 kg/ha 1 Crop - 2R Barley

16 Sampling Equipment & Protocol Gas Sampling Plexiglas vented chambers (0.1 m 2 soil surface area and 10-L headspace volume); 20 ml syringes and # 20 needles; 10 ml evacuated exetainers (stored in a Cooler) Sampling using a time step method - samples taken 15, 30 and 45 minutes after placing the cover on the chamber; ambient air samples are considered as samples at time 0 Lab Analysis Gas Chromatograph (Varian 3800 with ECD) Sampling Schedule Fall to fall (October October) fall fertilizer application Spring to spring (May May) spring fertilizer application Sampling Frequency Weekly High moisture events Data Processing Excel spreadsheet calculator - Dr Richard Farrell (U of S) Calculator tests both linear and quadratic models for fit 16 of the time step concentration data.

17 Year Dark Gray Luvisol Meteorological Summary Total Growing Season (May-September) Precipitation/Irrigation (mm) Black Chernozem Irrigated Dark Brown Chernozem* * Precipitation + Irrigation

18 N 2 O Monitoring Results Irrigated Dark Brown, 2010

19 N 2 O Monitoring Results Dark Gray Luvisol, 2009 Cumulative N 2O Emissions (g N ha -1 ) Cumulative N 2O Emissions (g N ha -1 ) Oct-08 Oct-08 Nov-08 Nov-08 Dec-08 Dec-08 Jan-09 Jan-09 Feb-09 Feb-09 Mar-09 Mar-09 Apr-09 Apr-09 May-09 May-09 Jun-09 Jun-09 Jul-09 Jul-09 Aug-09 Aug-09 Sep-09 Sep-09 Oct-09 Oct-09 Nov-09 Nov May 22 Seed Sept 1 Harvest F-C-0 F-E-120 F-E-60 F-U-120 F-U-60 Fall Banded Treatments Chambers installed just after fall banding No sampling over winter Date 1800 May 22 Seed Sept 1 Harvest S-C-0 S-E-120 S-E-60 S-U-120 S-U-60 Spring Banded Treatments Chambers installed just after spring banding and seeding Date

20 N 2 O Monitoring Results Dark Gray Luvisol, 2010

21 Cumulative N 2 O Emissions: Dark Gray Luvisol 21

22 Cumulative N 2 O Emissions: Black Chernozem 22

23 Cumulative N 2 O Emissions: Irrigated Dark Brown Chernozem 23

24 Fertilizer Induced Emission Factor EF annual (%) Appl n Time N Source N Rate kg ha -1 Dark Gray Luvisol Black Chernozem Irrigated Dark Brown Chernozem ave std err ave std err ave std err Fall Urea Fall Urea Fall ESN Fall ESN Spring Urea Spring Urea Spring ESN Spring ESN

25 N 2 O Emission Mitigation Summary Impact of N fertilizer management change (%) on mitigation of N 2 O emissions ( ) Management Change 120 kg N ha -1 Ave std err Fall Urea Fall ESN Fall Urea Spring Urea Fall Urea Spring ESN Fall ESN Spring ESN Spring Urea Fall ESN Spring Urea Spring ESN Positive average values indicate increased emissions; Negative average values indicate reduced emissions.

26 Summary Measured emission factor coefficients much lower than the 1.25% IPCC coefficient. Emissions are episodic with high spatial (regional) and temporal variability closely related to spring thaw, precipitation and irrigation events. Spring application of nitrogen fertilizer was the most effective means of reducing total emissions. Switching from fall applied nitrogen fertilizer to spring application results in 17% to 25% N 2 O emission reduction. Switching from fall applied urea to fall applied ESN results in 6% reduction. Changing from spring applied urea to spring applied ESN would result in a 5% reduction. 26

27 Summary High rates of N fertilizer caused more nitrous oxide emissions compared to the low N rates. Reduction in emissions was greater for high N treatments compared to the low N. In general, the ESN product resulted in lower emissions than uncoated urea. ESN could provide higher N use efficiency than uncoated urea, under similar conditions. If economically viable, producers could use ESN as a potential alternative to urea for improved crop production and reducing N 2 O emissions. Any disruption or reduction in crop N uptake during the growing season could result in higher emissions from the ESN or similar products. 27

28 Future Work Current Data Set Soil mineral N Soil N mineralization from SOM Crop N uptake and NUE Yield response modeling AFFIRM update Research Needs Fertilizer blends Split applications Variable rate Manure fertilizer blends Inhibitors Combining genetic, technological and management opportunities 28